Device for restraining a pointer of ammeter for the exposure meter in a camera

ABSTRACT

An exposure meter pointer clamping member having a planar surface is mounted to the movable ends of two spring members which extend from the camera body in parallel spaced relationship so that the planar surface is biased toward an opposing planar supporting surface whereby the pointer is restrained between the planar surfaces. A restraining member has a first position for opposing the force of the spring members to separate the planar surface and the planar supporting surface and a second position determined by the actuation of the shutter release mechanism to restrain the pointer.

United States Patent Kuramoto et a1.

[151 3,664,246 [451 May 23, 1972 [54] DEVICE FOR RESTRAINING A POINTER OF ANIMETER FOR THE EXPOSURE METER IN A CAMERA [72] Inventors: Yoshlo Kuramoto, Sakai-shi; Shotaro Inagaki, Okazaki-shi, both of Japan [21] Appl No.: 864,102

[30] Foreign Application Priority Data Oct. 15, 1968 Japan ..43/89968 [52] US. Cl. ..95/10 C [51] Int. Cl. .,G03b7/12 [58] E'eIdofSem-ch ..95/10C, 64R; 116/129N 5 6] References Cited UNITED STATES PATENTS 2,184,090 12/1939 Balsinger ..33/148 R 2,240,536 5/1941 Woxen ..33/172 R X 2,278,194 3/1942 Donnell ..33/147 D 3,464,333 9/1969 Aoki et al.. .....95/10 C 332,327 12/1885 Clark 116/119 497,454 5/1893 Muller ..281/42 785,215 3/1905 Hill .116/119 1,546,228 7/1925 Gray ..24/81 1,807,100 5/1931 Grafiet a1 ....40/23 A 1,847,184 3/1932 Hellerman..... ...1l6/1l9 1,898,429 2/ l 933 D0menego..... 1 16/1 19 1,976,465 10/ 1934 Thomson. 1 16/1 19 2,040,750 5/1936 Long ....40/11 3,308,784 3/1967 Miller ..1 16/1 19 1,089,348 3/1914 Rutty et al 24/259 PC 1,816,910 8/1931 Moore 116/119X 2,869,507 l/1959 Boyer ..116/173 3,425,389 2/1969 Sacco et a1 ..116/119 FOREIGN PATENTS OR APPLICATIONS 389,541 3/1933 Great Britain ..33/147 E 'Primary ExaminerSamue1 S. Matthews Assistant Examiner-Michael L. Gellner Anomey-Watson, Cole, Grindle & Watson ABSTRACT has a first position for opposing the force of the spring members to separate the planar surface and the planar supporting surface and a second position determined by the actuation of the shutter release mechanism to restrain the pointer.

5 Claim, 7 Drawing Figures Patented May 23, 1972 2 Sheets-Sheet 1 FIG.2

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2 Sheets-Sheet 2 *ZZZQ DEVICE FOR RESTRAINING A POINTER OF AMMETER FOR THE EXPOSURE METER IN A CAMERA BACKGROUND OF THE INVENTION In the prior art the exposure meter pointer is restrained at a position in compliance with the brightness of an object at the initial stroke of the releasing operation in order to control the diaphragm opening size and/or the shutter speed in relation to the position of the deflected pointer. Then exposure is effected by the continuation of the stroke of the releasing operation.

In I such devices the pointer is swung along the pointer receiver rigidly fixed to the camera main body and is pressed down to the pointer receiver by turning a pointer arresting member in the shape of a lever operated by a spring interlocked with the initial stroke of the release rod.

However, in such a construction as described above, the restraining edge of the pointer arresting member does not always contact perpendicularly with the pointer at any deflected angular position of the pointer, so that the pointer, when pressed, is turned aside due to a minute component force in the deflected direction, thereby resulting in that it will not be accurately restrained at its deflected position.

In addition, due to the necessary clearance where the pointer lever type arresting member is pivoted on the camera main body, it is impossible to accurately restrain the pointer, thereby producing a minor exposure error.

SUMMARY OF THE INVENTION This invention relates to a device for restraining the pointer in a camera in which a pointer arresting member is supported by two parallel springs, and one ends of which are rigidly fixed to the camera body so that the pointer arresting member has a tendency to press the pointer onto the pointer receiving surface at all times.

A feature of the present invention is to cause the pointer arresting member to travel parallel with respect to the pointer receiver.

Another feature of the present invention is that the pointer arresting member comes into contact perpendicularly with the pointer, and presses it down perpendicularly to the pointer receiving surface, regardless of the deflected angular position of the pointer.

Another feature of the present invention is that an equalized pressing force is provided at all times whenever the pointer arresting member presses the pointer to the pointer receiver and arrests it regardless of any deflected angular position of the pointer.

A further feature of the present invention is to restrain the pointer by interposing it between two parallel surfaces of the pointer arresting member and the pointer receiver, thereby preventing any undesirable force which may otherwise be imposed on the pointer and to preventing vibration when the pointer arresting member is arrested.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an embodiment of the present invention;

FIG. 2 is a front view of that embodiment showing the the pointer not restrained;

FIG. 3 is a front view of that embodiment showing the pointer restrained;

FIG. 4 is a perspective view of another embodiment of this invention;

FIG. 5 is a perspective view of that further embodiment of this invention;

FIGS. 6A and 6B are perspective views showing modified embodiments of parallel springs used in this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to FIGS. 1 3, pointer 3 of the ammeter, rigidly mounted on camera body I. is so disposed as to be able to swing along surface 4a of supporting member 4 which is also rigidly mounted on camera body 1, and is positioned at its deflected angle in compliance with the brightness of an object.

Pointer arresting member 5 is composed of a clamping plate 5a of a similar shape to supporting plane 4a, a vertical retaining rod 5b supporting clamping plate 5a, and a flanged engaging portion 5c at the top of rod 5b.

On vertical retaining rod 5b are rigidly fixed the ends of parallel springs composed of leaf springs 6a'and 6b of a similar shape, which are substantially horizontally laid in parallel with one another. On the other ends of the springs are tightly fixed a mounting plate 7 which is rigidly mounted on the vertical wall of camera body 1 beside the pointer receiver. Clamping plate 5a is provided with a tendencyto descend vertically, on account of parallel springs 6a and 6b, and remaining parallel with supporting plane surface 4a. One end of restraining lever 8 pivoted on camera body 1 at pin hole 8a and having a tendency to rotate counterclockwise by means of a spring or any other means not illustratedherein, maintains engagement with the flanged engaging portion 5c at the top of vertical retaining rod 5b at all times and pushes up pointer arresting member 5 against parallel springs 6a and 6b, by the swinging tendency of lever 8, until an elevated stationaryposition is defined by a pin 8b.

As lever 8 swings clockwise in conjunction with the initial stroke of the shutter releasing member not illustrated herein, it is interlocked with the release rod or with such a mechanism in a single reflex camera as the automatic controlling mechanism of a pre-set diaphragm activated prior to the shutter operation and/or with a reflector operating mechanism, etc. I

Further, as lever 8 swings clockwise, clamping plate 511 of pointer arresting member 5 travels perpendicularly towards supporting plane surface 4a so as to keep both surfaces parallel to each other by means of parallel springs 6a and 6b.

' Clamping plate 5a comes into contact with pointer 3 which rotates parallel to supporting plane surface 4a, at right angles to the rotating plane of the pointer, and presses pointer 3 at right angles to supporting plane surface 40. Therefore, in this case, no pressing force acts on the pointer in its deflected angular direction within its rotating plane, so that the pointer is accurately restrained at its deflected angular position and no error is produced when the pointer is arrested. Also the pressing force for arresting is equalized regardless of the deflected angular position of the pointer.

Consequently, the pointer can be restrained by a pointer receiving and pointer arresting portions formed as a planar shape instead of being restrained by an edge-like portion thereby contributing to higher accuracy and longer durability of the exposure meter.

The embodiment shown in FIG. 4 shows springs 16a and 16b positioned at the center of the deflecting range of pointer 3, disposed in the direction normal to and in front of vertical retaining rod 5b, and are rigidly mounted to the camera main body by mounting plate 17.

FIG. 5 is another embodiment in which a cross-formed retaining plate 15b is provided instead of a vertical retaining rod and two pairs of parallel springs 26a, 26b and 36a, 36b are horizontally and rigidly fixed at each side of retaining plate 15b, and are mounted perpendicularly on the camera body by means of mounting plates 27 and 37. In this embodiment, it is desirable from the view point of stability that both parallel 1. Apparatus for clamping a light sensitive exposure meter pointer in a camera having a shutter release mechanism, comprising:

a supporting member having a planar supporting surface mounted to the camera body so that said pointer traverses parallel to said planar supporting surface;

two spring members mounted to said camera body and extending therefrom in parallel spaced relationship;

a clamping member mounted to the movable ends of said spring members and having a planar surface substantially corresponding to said planar supporting surface in opposed spaced relation thereto, said spring members tending to force said planar surface towards said planar supporting surface; and

a restraining member having a first position for opposing the force of said spring members to separate said planar surface and said planar supporting surface and having a second position determined by actuation of said shutter release mechanism wherein said pointer is restrained between said planar surface and said planar supporting surface.

2. Apparatus as in claim 1, wherein said clamping member includes a retaining member projecting from said planar surface substantially at a region thereon corresponding to the deflection angle center of said pointer and contacting said restraining member; and said movable ends of said spring members are substantially perpendicularly mounted to said retaining member.

3. Apparatus as in claim 2 wherein said planar surface, said planar supporting surface, said retaining member, and said two spring members lie substantially in the same plane.

4. Apparatus as in claim 2 wherein said retaining member and said two spring members lie in substantially the same plane and are substantially perpendicular to said planar surface and said planar supporting surface.

5. Apparatus as in claim 2 further comprising an additional two springs members mounted to said camera body and extending therefrom in parallel spaced relation and said retaining member includes a transversely extending member, the movable ends of said two spring members and said additional spring members are respectively symmetrically mounted to said transversely extending member on opposite sides of said retaining member. 

1. Apparatus for clamping a light sensitive exposure meter pointer in a camera having a shutter release mechanism, comprising: a supporting member having a planar supporting surface mounted to the camera body so that said pointer traverses parallel to said planar supporting surface; two spring members mounted to said camera body and extending therefrom in parallel spaced relationship; a clamping member mounted to the movable ends of said spring members and having a planar surface substantially corresponding to said planar supporting surface in opposed spaced relation thereto, said spring members tending to force said planar surface towards said planar supporting surface; and a restraining member having a first position for opposing the force of said spring members to separate said planar surface and said planar supporting surface and having a second position determined by actuation of said shutter release mechanism wherein said pointer is restrained between said planar surface and said planar supporting surface.
 2. Apparatus as in claim 1, wherein said clamping member includes a retaining member projecting from said planar surface substantially at a region thereon corresponding to the deflection angle center of said pointer and contacting said restraining member; and said movable ends of said spring members are substantially perpendicularly mounted to said retaining member.
 3. Apparatus as in claim 2 wherein said planar surface, said planar supporting surface, said retaining member, and said two spring members lie substantially in the same plane.
 4. Apparatus as in claim 2 wherein said retaining member and said two spring members lie in substantially the same plane and are substantially perpendicular to said planar surface and said planar supporting surface.
 5. Apparatus as in claim 2 further comprising an additional two springs members mounted to said camera body and extending therefrom in parallel spaced relation and said retaining member includes a transversely extending member, the movable ends of said two spring members and said additional spring members are respectively symmetrically mounted to said transversely extending member on opposite sides of said retaining member. 